<html>

<head>
    <script src="./vue.js"></script>
</head>

<body>
    <div id="app">
        <div>
            <p>{{msg}}</p>
        </div>
    </div>
</body>
<script>
    var app = new Vue({
        el: "#app",
        data: {
            msg: "I am Vue",
        }
    });
    console.log(app.$data.msg)
</script>

</html>